Glower for electrical incandescent lamps.



0. M. THOWLESS.

GLOWER r011 ELECTRICAL INOANDESGENT LAMPS.

APPLICATION FILED MAY 1, 1908.

982,751 Patented Jan.24,1911.

W MM

ORLANDO M. THOWLESS, O'F NEWARK, NEW JERSEY.

GLOWER FOR ELECTRICAL INCANDESGENT LAMPS.

Specification of Letters Patent.

Patented Jan. 24, 1911.

Application filed May 1, 1908. Serial No. 480,285.

To all whom it may concern:

Be it known that I, ORLANDO M. Tnow- LESS, a subject of the King of Great Britain, residing at Newark, in the county of Essex and State of New Jersey, have invented certain new and useful Improvements in Glowers for Electrical Incandescent Lamps, of which the following is a' specification.

My invention relates to glowers or illuminants for electrical incandescent lamps, and more particularly to filamentary glowers, althou h tubes, rods or other forms may be made or the purpose, the said glowers being made from finely powdered materials, and when finished shall be conductive and luminous under the action of a suitable electric current.

7 The object of this invention is to produce glowers from powders which are not readily made into filaments by ordinary methods either through a lack of ductility or where it is only possible to make such filaments by long and expensive processes.

One form of this invention consists in glowers made' from refractory metals, in powdered form, such as tungsten, molybdenum, titanium, zirconium, niobium, vanadium, chromium, ruthenium, osmium, manganese or metals of these different groups or a mixture of two or more such refractory metals.

Another form consists in 'glowers having, when finished, a high electrical resistance as compared with solid metal filaments, so that shorter and thicker glowers may be used ,than those made entirely of metal. In this form the powders composing the glowers can be so changed and arranged as to enablethe maker to control and plan any resistance for them at a given length and cross-section, and this is done by adding a varying quantity of refractory .metallic oxid material in powder to the metallic powders hereinbefore mentioned. The refracoxid powders are not used with the metal powders. In either form it is not necessary to add an agglutinant to the powders, for any material which it is, necessary to burn away will leave the glower in a spongy condition, which this invention contemplates the avoidance of.

In regard to the plan of controlling the resistance for the same length and crosssection it may be stated that where the metallic and oxid substances are mixed together, the larger the amount of oxid added to a given amount of metal powder the higher will the resistance be, and this can be increased to any degree, by the addition of more of the oxid powder, for the same dimensions of the glower.

This invention has for its object the pro duction of a "lower made from materials in a finely d'ivi ed state, which shall answer the same purposes as a ductile wire glower and shall be ductile during its manufacture, and be capable of being handled and worked in the same manner as if made of ductile wire.

In carrying outmy invention I take a cartridge or hollow cylinder of some metal or alloy which is ductile and malleable, and pack it with the powder or powders of which the glower-is to be composed. The cartridge or hollow cylinder, which, for future reference, I will call the cylinder, may be made of copper, brass, platinum, Germansilver, alummum, magnesium, tin, lead or the like, or any alloy of these.

As an illustration of this invention, and so that it can be properly understood, I will give here one form of cylinder metal with a form of refractory metal powder, also one form of oxid material with one of powdered refractory metal, with the method of making the same into glowers. For example, an aluminum cylinder is packed with metallic tungsten in powder, or if the high resistance glower is desired, the cylinder is packed with powdered tungsten and powdered oxid of thorium intimately mixed, and any air or occluded gases exhausted therefrom, as otherwise a rupture of the walls of the cylinder might be caused during the operation of drawing it down into wire. The packed cylinder is then treated as though made of being perfectly pliable and ready for outling into lengths, and, if so desired, may be at onceiformed into the proper sha e for electrical incandescent lamps, but, efore using it for lighting purposes, the aluminum may be accomplished. after the 'glgii'ver is mounted in the lamp-bulb, during the process of exhaustion. 'When'the covering has been removed theglower may be raised toa very-high temperature 'for the purpose of sten' in powder in the one form of this invenmakinga still closer-union of its particles,

also to prevent a later shrinkage and to cause it to become a solid homogeneous glower.

In the foregoing agcylinder of aluminum is described as packedwith metallic tungtion ','or with. tungsten and oxid of thorium I in the other form, but, as previously stated,

the above was given to illustrate the invention and to show how the glowers are to be produced; it is therefore to be understood thatother metals and alloys may be used for the cylinder, such as copper, nickel, brass,

tin, lead, zinc, so, for the filling, owder other than platinum, German silver magnesium or the like. Al some refractory metallic tungsten may be employe as, for instance:

molybdenum, tantalum, niobium, vanadium, thorium, 3 zirconium, osmium, chromium manganese, ruthenium or the like, or a mixture of two or more refractory metals, but in all cases, whichever metal or combination of metals is used, it is necessary that they should be in a' finely divided state-that is to say-the powder should be fine when it is packed in the cylinder. Also, in regard to the oxid to be used with the metals, in some forms of glowers it will be found that other oxids than the one mentioned in the example, viz., oxid of thorium, may be very useful, such as any of the rare-earth oxids, or the oxids of magnesium or aluminum, or any of the refractory metallic oxids. It is better to use only a single oxid with the metallic powder,as a combination of two or more oxids becomes conductive under certain conditions, though this would not be likely in in a flashing-jar from vapor of halogen or other salts of metals, in an atmosphere of hydrogen or other suitable gas, by means of an electric current traversing them. While it may be better in most cases to deposit the same metal or metals as used in the glowers, yet any of the hi 'hly refractory metals or a combination of them may be used for this purpose. Generally this deposition should take place after the glowers'have received the high temperature hereinbefore mentioned.

It will be found that a glower made in the manner described is a very compact and uniform article, as drawing the wire through holes in a draw-plate causes the powdered material to pack ver closely, owing to the heavy pressure it HIM ergoes, therefore, when the (.Otltlllfl' metal is removed the glower material seems like solid wire.

The glowers are attached to the leading-in wires by means of welding or with proper cement or by mechanical means, or in any other suitable manner.

In the accompanying drawings: Figure 1 is a View of an electric lamp, illustrating my invention, with glower completed. Fig. 2 isa longitudinal central sectional view of a hollow cylinder before the same is packed with the glower material. Fig. 3 isa similar view of 'the cylinder packed with the glower material before it has been subjected to the working operations. Fig. t is an enlarged view of a portion of the wire, as it may be termed, after being drawn, ready for the removal of the covering, a part of the latter being shown as broken away to display the construction of the wire. 7

Similar letters refer to similar parts in all the figures, in which A is the lamp-bulb; B, a

the glass stem in which the leading-in wires are sealed; C, the cement, weld or other joint connecting the leading-in wires with the glower; D, the glower as completed; E, the covering cylinder; F, the glower material packed in-the cylinder, E; G, the supports for the glower; while the two letters, H H, show the leading-in wires.

Having thus described my invention, what I claim is:

1. A glower for an electrical incandescent lamp consisting of a light-emitting body composed of tungsten and refractory oxid covered with refractory metal.

2. A glower for an electrical incandescent lamp consisting of a light-emitting body of tungsten and oxid of yttrium covered with refractory metal.

3. An incomplete glower for an electrical incandescent lamp composed of a mixture of refractory metallic powder and refracgory oxid powder in a close and compact orm.

4. The method of making, filaments for refractory powdered material; exhausting the airfrom the same; drawing the cylinder and contents to filamentary form and then removing the cylinder material.

7. The method of making glowers for electrical incandescent lamps which'consists in packing a hollow cylinder with powdered refractory conductive material; exhausting the air therefrom; drawing the cylinder and con- 4 tents to form an outer shell inclosing a compact continuous conductive core and shrinking the core into solid homogeneous filaments by means of a high temperature.

8. The method of making incomplete glowers for electrical incandescent lamps which COIlSlSlIS'iIl surrounding a body of refractory powder with ductile material; working the ductile material and inclosed refractory powder into filamentary form and removing the ductile material from the refractory material.

' 9. The method of making glowers for electrical incandescent lamps which consists in packing a hollow cylinder with refractory powdered conductive material; drawing said brittle material into filaments and cylinder and contents into a wire to form an outer shell inclosing a compact conductive core ;'removing the inclosing shell; shrinking the core into solid homogeneous filaments with the aid of a high temperature and then covering them with refractory metal.

10. The method of making glowers for electrical incandescent lamps which consists in shaping a cylinder containing refractory powder into filaments; heat-ing the filaments to a solid homogeneous condition and then coating them with refractory metal.

11. The method of making glowers forelectrical incandescent lamps which consists in surrounding a mass of refractory powder with ductile material, working the ductile material and inclosed mass of refractory powder into filamentary form, removing the ductile material from the refractory material, forming the refractory material into solid and homogeneous filaments under the action of a high temperature and covering them with refractory conductive material.

12. The method of making glowers for electrical incandescent lamps which consists in drawing a cylinder containing refractory rotecting the same from oxidation during the manufacture.

Signed at Newark in the county of Essex and State of New Jersey; this twenty ninth day of April; 1908.

ORLANDO M. THOWVLESS.

\Vitnesses:

Hunnn'r L. Tnownnss, ARTHUR J. THOWLESS. 

